A polycarbonate-polyorganosiloxane copolymer has high impact resistance, high chemical resistance, and high flame retardancy, and has been expected to find utilization in a wide variety of fields, such as the field of electrical and electronic equipment and the field of an automobile.
The polycarbonate-polyorganosiloxane copolymer can be produced by, for example, an interfacial polymerization reaction (Patent Document 1). The polycarbonate-polyorganosiloxane copolymer obtained after the polymerization can be subjected to a powdering/granulation treatment with a kneader or the like to be turned into a powder. The powder is subjected to various steps while being, for example, pneumatically transported, and then the resultant is separated into a gas and a powder with a separator. Thus, a target polycarbonate-polyorganosiloxane powder can be obtained. The resultant powder can be, for example, further pelletized with a pelletizer or the like to be turned into various molded bodies. The pneumatic transportation has advantages over mechanical transportation, such as the simplification of a transportation line, the prevention of the scattering of harmful dust, and the prevention of the inclusion of foreign matter into a substance to be transported.